1. Field of the Invention
The present invention relates to heat-transfer devices and to gas turbine combustors having the same.
2. Description of Related Art
Combustor liners, turbine blades, heat exchange equipment, fins, steam boilers, and other gas turbine components are adapted to promote heat transfer between a fluid and a solid in processes such as cooling and heat exchange therein. Varieties of structures for such a heat transfer promotion are discussed in accordance with the specifications required of these components.
For example, combustors for power-generating gas turbines are required to maintain necessary cooling performance with low pressure loss causing no deterioration in gas turbine efficiency, and thereby to maintain reliability of structural strength. In addition, reduction in emission levels of the nitrogen oxide (NOx) gases generated in the combustors is required in terms of paying due attention to environmental issues. The reduction in NOx gas emissions can be achieved by using premixed combustion, in which a fuel and air are mixed well prior to burning, and by burning this mixture at a fuel-air ratio smaller than a stoichiometric ratio of the fuel to air.
A heat-transfer device (heat transfer structure) of a gas turbine combustor, designed with the above in mind, is proposed in JP-2001-280154-A. In the heat-transfer device (heat transfer structure) of JP-2001-280154-A, longitudinal vortex generating devices that generate spiral vortices (longitudinal vortices) having a central axis of their swirling in a flow direction of high-pressure air from a compressor are disposed on an outer circumferential surface of a cylindrical combustor liner along which the high-pressure air flows. The longitudinal vortex generating devices are arranged side by side both axially and circumferentially on the combustor liner, and the longitudinal vortex generating devices arranged adjacently to each other circumferentially on the combustor liner are formed to swirl the respective vortices in directions opposite to each other. In addition, turbulent-flow enhancers that destroy a boundary layer generated in the high-pressure air are disposed between the longitudinal vortex generating devices arranged side by side axially on the combustor liner.